Mysql auto_increment recount of have id start at 1

Method 1

delete from test;
alter table `test` auto_increment=1
(for good, you can set AUTO_INCREMENT to start with any value)
Tip: if there are a lot of table columns and data, the speed will be slow, such as more than 900,000 pieces, will be more than 10 minutes.

Method 2

truncate table test
(benefit, simplicity, AUTO_INCREMENT value start counting again)

In general, we can use the second one. Remember that all records are deleted completely.